MUSCLE-INVASIVE BLADDER-CANCER TREATED WITH EXTERNAL-BEAM RADIOTHERAPY - PROGNOSTIC FACTORS

Purpose: To determine the relationship of several potential prognostic factors to the outcome measures of pelvic control, freedom from metas tases, and overall survival for bladder cancer patients treated with d efinitive external beam radiotherapy. Methods and Materials: The recor ds of 135 patients treated with high-dose, planned continuous-course, external beam radiotherapy for muscle-invasive transitional cell bladd er cancer were reviewed. These patients were treated to an average tot al dose of 6588 +/- 475 cGy with an average fractional dose of 207 +/- 18 cGy using megavoltage. Median potential follow-up for all patients , including those who died, was 249 months. Results: The actuarial res ults at 5 year were 31% pelvic control, 58% freedom from metastases, a nd 26% overall survival. In the univariate analyses, several factors w ere correlated with disease outcome including clinical stage, tumor mo rphology, gross total transurethral resection (TURBT), findings at bim anual exam after TURBT, clinical perivesical extension, age, and clini cal complete response at first follow-up cystoscopy (Clinical-CR). A C ox proportional hazards model revealed that only Clinical-CR was indep endently predictive of pelvic control. In terms of freedom from metast ases, only Clinical-CR and clinical stage were significantly associate d with outcome in the multivariate analysis. When the multivariate ana lysis was restricted to T2 and T3 tumors only, then clinical perivesic al extension replaced stage as being associated with freedom from meta stases. The only factors significantly related to overall survival in the Cox proportional hazards model were Clinical-CR, age, and complete TURBT; stage was of borderline significance when only pretreatment fa ctors were considered. Conclusions: Clearly, the most important progno stic factor was Clinical-CR. The pretreatment factors of stage, clinic al perivesical extension, and gross total TURBT also correlated with o utcome, but, to a lesser degree. For patients medically unfit for radi cal cystectomy radiotherapy is a viable option, particularly for selec ted patients. Patients with T4 tumors are poor candidates for definiti ve radiotherapy and should be treated palliatively if they cannot tole rate systemic therapy.